例として2つの方法を示します(いくつかの点で類似しています):
例1:
$sql = 'SELECT count(*) FROM `TABLE`;';
for ($i = 1; $i <= 2; $i++) {
try {
$nb = $pdo->query($sql)->fetchColumn();
if (is_int($nb)) {
// OK
break;
}
} catch (PDOException $e) {
//Oups
if ($i == 1) {
// First time ? retry
$pdo = new PDO($dsn, $user, $password);
} else {
// Second time, KO
$nb = "(unknown)";
echo 'PDO Connection failed: ' . $e->getMessage().'. ';
}
}
}
例2:
// check
try {
$pdo->query('select 1;')
//OK
} catch (PDOException $e) {
//Oups => reconnect
$pdo = new PDO($dsn, $user, $password);
}
// Should be good
$sql = 'SELECT count(*) FROM `TABLE`;';
$nb = $pdo->query($sql)->fetchColumn();